Polycyclic insecticidal compounds



Unitec POLYCYCLIC INSECTICIDAL COMPOUNDS Rex E. Lidov, Denver, Colo.,assignor, by mesne assignments, to Shell Development Company,Emeryville, Califl, a corporation of Delaware 9 Claims. (Cl. 167-30)This application is a division of copending application Serial No.156,716 filed April 18, 1950, now Patent No. 2,676,132.

This invention relates to new compositions of matter possessingunexpectedly high toxicity to insect life and particularly to insectlife but little affected by the halogenated hydrocarbons and theirderivatives hitherto employed.

The copending applications of Lidov, Serial No. 795,- 140 filed December31, 1947, now Patent No; 2,635,979, and Serial No. 45,573 filed August21, 1948, now Patent No. 2,635,977, relate to a group of polycyclichalogenated hydrocarbons and derivatives thereof which show not onlyunexpectedly high insecticidal activity but in addition a surprisinglyhigh order of stability to reagents which normally readily degrade thepreviously known organic halogenated insect toxicants, and they alsorelate to the methods for producing these new compositions.

This invention relates, more specifically, to new members of the abovedescribed group of polycyclic halogenated hydrocarbons and theirderivatives which possess in addition to the common properties of thosecompounds previously disclosed new properties in such marked degree asto render them particularly suitable and valuable in combatting pestsbut little affected by many or most of the family of compounds to whichthese members belong.

One object of this invention is to produce organic materials possessinga high order of insecticidal activity.

Another object of this invention is the production of a group' ofinsecticidally active organic compounds which are stable, under ordinaryconditions of use, to the usual degradative action of acids andalkalies.

Another object of this invention is the production of a group of stable,insecticidally active compounds with varying degrees of residualinsecticidal activity.

Still another object of this invention is the production of organicmaterials possessing a high order of in secticidal activity with respectto insect species which, in general, are but poorly controlled bypreviously known halogenated organic insecticides.

A still further object of this invention is to provide means for theproduction of these new and valuable Other objects, features,capabilities and advantages are comprehended by the invention, as willlater appear and as are inherently possessed thereby.

While, in recent years, a number of halog llatedl ydrocarbons or simplehydrocarbon derivatives have been discovered which possess, to a highdegree, the property of toxicity to various forms of insect life thesematerials all possess limitations which to a lesser or greater extentreduce their utility and applicability. Thus, except for the compoundsdisclosed in the above cited copending applications all of the hithertoknown organic halide insect toxicants have possessed the tendency tolose halogen and concomitantly their insecticidal activity.

2 ,7 l 7 ,85 l Patented Sept. 13, 1955 Moreover, all of the previouslydiscovered halogenated hydrocarbon toxicants, while extremely effectiveagainst many varieties of insect pests, are of limited or little use incombatting many other equally undesirable insect species. This fact is,in itself, not particularly surprising in view of the enormous number ofinsect species known and the large differences which can exist betweenspecies. It is therefore hardly surprising that no single insecticidalcompound can be successfully used against all species.

Somewhat less understandable is the fact that certain large classes ofnoxious insects have'possessed substantial immunity to all of thepreviously discovered halogenated insect toxicants, including thosespecifically disclosed in the copending applications hereinabovereferred to.

I have now found that some classes of insects heretofore uncontrollablethrough the use of halogenated hydrocarbon toxicants are highlysusceptible to the action of our new composition of matter. Since theseclasses of insects have, until now, been relatively resistant tocompounds of this general type the fact that they are attacked by ournew composition is both novel and unanticipated. This fact is even moresurprising inasmuch as my new compounds are structurally quite similarto those disclosed in the copending applications hereinabove cited; theyare actually stereoisomers of the compounds disclosed therein. Like thepreviously disclosed isomers my new compounds, while posessing a veryhigh order of insecticidal activity, have their halogen atoms so firmlybound as to make them stable under conditions of alkalinity which causethe older halogenated insecticidal materials to lose halogen, and,simultaneously, to lose activity.

Significant, too, is my discovery that the product obtained whencyclopentadiene is caused to react with 1,2,3,4,7,7 hexahalobicyclo(2.2.1) 2,5 heptadiene in a Diels-Alder reaction is different from theproduct obtained when a similar reaction is carried out betweenhexahalocyclopentadiene and bicyclo-(2.2.l)-2,5-heptadiene.

My new compositions of matter are obtained directly by reacting one tofour moles of a cyclopentadiene with l,2,3,4,7,7 hexahalobicyclo (2.2.1)2,5 heptadiene. The new compositions thus obtained possess the basiccarbon skeleton of a series of not more than five linearly fusedbicyclo-(2.2.l)-heptane rings, the fusion occurring through thetwo-carbon atom bridges of the bicyclic rings to produce a structurecontaining two terminal five-carbon atom rings, each of which ischaracterized by an ethylenic bond in its unfused two-carbon atombridge. The basic carbon atom skeleton, in planar representation is,therefore, the one illustrated immediately hereinattached to each of thetwo carbon atoms of the unfused two-carbon atom bridge.

While the foregoing description of my new compounds characterizes thesecond terminal five-carbon ring as containing at least one monovalentcomponent attached to each of the two carbon atoms of the unfusedtwo-carbon atom bridge, it may in fact have two such monovalentcomponents attached to each of these two-carbon atoms. These two-carbonatoms may also be joined by a double bond instead of by a single bondonly; in this case, of course, each of them would bear, additionally,only a single monovalent component.

The number of fused bicycloheptane rings present in the molecule will bedetermined by the number of moles of cyclopentadiene reacted with thehalogenated polycyclic diene. When the two reactants are reacted in amole to mole ratio the new molecule will contain only two fusedbicycloheptane rings.

The cyclopentadiene chosen for the reaction can be eithercyclopentadiene itself or a substituted cyclopentadiene such, forexample, as methylcyclopentadiene, dirnethylcyclopentadiene, etc. Inthis way, a variety of alkyl, cycloalkyl, arylalkyl and arylsubstituents and derivatives thereof may be introduced into theunhalogenated ring or rings of my new compound. For ease of referenceall such groups will hereinafter be called alkyl groups and the wordalkyl will not be employed in its more restricted meaning withoutspecifically noting that fact.

Halogen derivatives in which the halogen is attached to carbon atomsother than those of the unfused two-carbon atom bridge of the originallyunhalogenated terminal five-carbon atom ring can be obtained byhalogenating the primary compounds resulting from the Diels-Alderreaction. Subsequent to halogenation the application of the usualprocedures for producing esters, alcohols and ethers from halo compoundswill give rise to other of my new compounds.

Contemplated by and included within the scope of my present invention ashereinabove set forth are the compounds which are obtained by adding avariety of reagents to the ethylenic bond of the unhalogenated terminalfivecarbon atom ring. Thus, for example, acetic acid can be added to thedouble bond of the unhalogenated ring in the presence of sulfuric acidto produce an acetoxy derivative of the parent compound. This acetoxyderivative can be hydrolyzed to produce an alcohol and the alcohol soobtained can be further oxidized to form a ketone. Similarly, halogenscan be added to the aforementioned double bond to produce dihaloderivatives of the original compound, or alternatively, the halogenacids, HX, can be added to the double bond to produce monohaloderivatives of the original compound. In like fashion, hydrogen can beadded to the same double bond to produce a dihydro derivative. It shouldbe noted that in all such reactions the double bond in the halogenatedterminal ring remains unchanged. All such derivatives of the originallyformed Diels-Alder adduct and the additional compounds of like nature,which, as a result of my disclosure, skilled chemists will recognize canbe prepared, are all properly included within the scope of my invention.

These compounds of my invention may also be represented by the followingstructural formula:

in which X represents a halogen atom, n has an integral value from 0 to3, both inclusive, and m and p each has an integral value from 0 to 4,both inclusive, Y and Z are preferably but not necessarily selected fromthe group of monovalent atoms and radicals consisting of -COOH, coon, orO:N

and a and b are representative of bonds attached to monovalent atoms andradicals selected from the above defined group or to each other. When aand b are attached to each other there will, of course, be introduced asecond double bond into the polycyclic ring structure shown.

In the group of atoms and radicals set forth above, R represents asaturated hydrocarbon radical, an unsaturated hydrocarbon radical, asubstituted derivative of a hydrocarbon radical, or a substitutedderivative of an unsaturated hydrocarbon radical. R and R in thestructural formula shown may represent one or more halogen atoms or oneor more substituting radicals as defined above for R which may beattached to carbon atoms forming the indicated rings of the structureshown.

For the sake of simplicity the substituents in the pentacarbon cycles orrings, other than the completely halogenated terminal ring arerepresented by the symbol R m and R p, where in may range over anintegral value from 0 to 4, both inclusive. More than one of these Rtype substituents may be present attached to the carbon atoms of thepentacarbon cycle, the number of groups so attached being defined by theintegral values of m and p. The values of m and p thus define the numberof substituents in each cycle. Since, in these rings, each carbon atommust be attached either to a substituent, as previously defined, or to ahydrogen atom, the number of hydrogen atoms remaining attached to carbonatoms in each pentacarbon ring is given by the value of (4m). These Rtype groups may arise through the use of substituted cyclopentadienes inthe preparation of the polycyclic dienophiles from which some of my newcompositions of matter may be considered to be derived, as the result ofhalogenation reactions, or as a result of other reactions utilized tointroduce such groups into the pentacarbon ring involved. They may alsoarise through the use of substituted cyclopentadienes in the reaction ofsuch dienes with l,2,3,4,7,7-hexahalobicyclo-(2.2.l )-2,5-heptadiene.

In the formula indicated the symbols G and T may also represent one ormore substituents which are selected from the group consisting of H,halogen atoms, R and =R. R is here used in the same sense ashereinbefore defined; =R represents a saturated or unsaturatedalkylidene or cycloalkylidene radical or a substituted derivativethereof. By an alkylidene radical, a radical of the general type whereinR is used in its previously defined sense, is'

meant. A cycloalkylidene radical is one possessing the structure nhaving any desired integral value including and greater than one.

If alkylidene or cycloalkylidene radicals are represented by the symbolsG or T, no other groups are attached to the endomethano carbon atoms. Inany other case two of the other members of the indicated group,independently selected, will be attached to that carbon atom.

The alkylidene and cycloalkylidene type substituents may arise throughthe use of fulvenes in the preparation of the polycyclic dienophilesfrom which my new compositions of matter may be considered to be derivedor through the use of fulvenes for reaction with thehexahalobicycloheptadienes. Other members of the group may arise in thesame fashion as has been hereinabove described for R and R Those skilledin the art will at once recognize that a selection of the monovalentatoms and radicals in the defined group for attachment to the bonds aand b and in place of Y and Z might so be made as to lead to compoundswhich are unstable. Such a situation would exist, for example, if thesymbol Y is taken to represent a hydroxyl radical and the bond a issimultaneously attached to a hydroxyl radical. In such a case thecompound represented would, in fact, be nonexistent since theconfiguration shown would lose the elements of water to form a ketone.It is my explicit intention that all of the stable compounds which areobtained as a result of the stabilization of the numerous compoundswhich can be represented by the above shown general structural formulaethrough the loss of H20, HOR, H2S, SHR, NHz, NHzR, NHRz or hydrogenhalide are to be included within the scope of my invention.

In other cases, it will be noted, the selection of appropriate membersof the group will lead to compounds which by the usual procedures oforganic chemistry might be expected readily to react with simplereagents with the loss of the elements of H20, HOR, SHR, NHz, NHzR,NI-IRz or hydrogen halide to produce new derivatives. This, for example,would be the case of a and b" were each attached to a hydrogen atom andY and Z were respectively attached to a halogen atom and to a hydroxylradical. All of the derivatives of the structure shown which can beformally derived by loss of the elements of H20, HOR, HzS, SHR, NH3,NHzR, NHR2 or hydrogen halide therefrom are specifically included withinthe scope of my invention regardless of the procedures employed in theirpreparation.

Similarly, it is recognized that such selection of the monovalent atomsand groups will in some cases lead to representations of compounds whichwill, in general, be more stable, and hence will exist, in tautomericmodifications of the structures thus represented. This would be the caseif, for example, Y is taken to represent a hydroxyl radical and thebonds a and b are joined to each other to form a new double bond. Inthis case the compound represented by the indicated structure will be aketone. The stable compounds which result from all such tautomericshifts are also explicitly intended as within the scope of my invention.

The reaction product which is obtained when one mole of1,2,3,4,7,7-hexachlorobicyclo-(2.2.1)-2,5-heptadiene is reacted with onemole of cyclopentadiene, in accordance with the present invention, orwhen one mole of hexachlorocyclopentadiene is reacted with one mole ofbicyclo-(2.2.1)-2,5-heptadiene as more particularly described andclaimed in my copending application Serial No. 45,573 filed August 21,1948, is represented by the planar structural formula which followsimmediatelyhereafter.

o1 H H 01 l i H i 0101 Hon 01 i H Yet each of the two compoundsrepresented by a single graphical structure is physically and chemicallydistinct from the other. Hence, in order to illustrate and explain thedifferences between the compounds which may properly be represented bythe planar structures hereinabove set forth, it will be necessary todiscuss briefly the stereo chemical configurations of such compounds.

Given a simple bicycloheptene compound such as I it is believed that thefour carbon atoms 2,3,5, and 6 may be considered to lie in the plane ofthe paper with the carbon atoms 1 and 4 above that plane and with thecarbon atom 7 raised above that plane even further than atoms 1 and 4.The bonds joining the atoms H and X and H and Y to carbon atoms 2 and 3are then thought to be disposed above and below the plane of the paper.The planar structure II consequently (disregarding optical isomerism)corresponds to three stereoisomers: these structures may be representedby three dimensional drawings, thus:

If both X and Y are taken to represent chlorine atoms, then, inaccordance with the nomenclature most commonly employed, the compound(a) is atransdichloro compound, (b) is an exo-cis-dichloro compound and(c) is an endo-cis-dichloro compound.

It is further widely believed that when the attachments X and Y areparts of a ring system containing not more than six atoms the rings thusfused must assume either an exo-cis or an endo-cis configuration;presumably, a trans configuration is necessarily excluded.

If a compound such as I, above, is further examined, it follows that,four theoretically possible stereoisomers are represented:

(1) a compound in which the second 6 membered ring is fused in theexo-cis position and in which the endomethano bridge in the second ringis oriented, in a general sense, in the same direction as theendo-methano bridge in the first 6 membered ring.

(2) a compound in which the second 6 membered ring is fused in theexo-cis position but in which the orientation of the second endo-methanobridge is directed in the opposite sense from that of the first.

These may be shown three dimensionally as:

I shall henceforth speak of compound (d) as possessing an exo-exoconfiguration and further I shall refer to both ring A and ring B inthat compound as possessing an exo configuration. I shall henceforth saythat compound (e) possesses an exo-endo configuration and further Ishall say that ring A in compound (e) possesses an exo configurationwhile ring B of compound (e) possesses an endo configuration.

The other two compounds represented by the planar structure I are thecorresponding variants in which the second fused ring is in the endo-cisposition. These may be shown as:

Henceforth I shall refer to compound (f) as possessing an endo-exoconfiguration and I shall further state that ring A in compoundpossesses an endo configuration and that ring B in compound (1)possesses an exo configuration. Similarly I shall refer to compound (g)as possessing an endo-endo configuration and I shall further say thatboth rings of compound (g) possess an endo configuration.

I do not know with certainty which of the configurations shown shouldproperly be assigned to my various compounds. It is my present beliefthat the compound formed when one mole of hexachlorocyclopentadienereacts with one mole of bicycle-(2.2.1)-2,5-heptadiene possesses eitherthe exo-exo (d) configuration or the endo-exo (1) configuration. I shallhenceforth call the configuration obtained in this fashion the alphaconfiguration and shall shall the series of compounds so obtained thealpha series. I further believe that the compound formed whencyclopentadiene reacts with l,2,3,4,7,7-hexachlorobicyclo-( 2.2.1-2,5-heptadiene possesses either the endo-endo (g) configuration or theexoendo (e) configuration. I shall henceforth call the configurationobtained by this second reaction method the beta configuration and shallcall the series of compounds so obtained the beta series. I believefurther that if the first of these compounds (alpha) possesses theexoexo configuration then the second of these compounds (beta) possessesthe endo-endo configuration whereas if the alpha compounds possess theendo-exo configuration then the beta compounds possess the exo-endoconfiguration.

I believe that it is obvious that the discussion of configuration hasnot, to this point, considered the spatial relationships existing whenthe compound under consideration is one possessing more than two fusedbicycloieptane rings. It follows, however, from what has already beensaid that such addition of one mole of a cyclopentadiene to a mole ofany given fused polycyclic compound can lead to the formation of fourstereoisomers. But since from my present knowledge of reactions of thistype it appears that they tend to proceed to give stereochemically pureproducts the nature of which is determined primarily (although notnecessarily exclusively) by the reactants, it follows that subsequentaddition of cyclopentadienes to the tetracyclic primary products willactually lead to the formation of only one of the four theoreticallypossible additional configurations. From my present standpoint it isequally important to note that such additional reactions ofcyclopentadienes with the four (alpha, beta, etc.) primary stereoisomersof hexahalotetracyclododecadiene will in each case involve substantiallythe same reaction, viz., the addition of a cyclopentadiene to the doublebond of an unhalogenated bicycloheptane ring system; it thereforeappears reasonable to assume that the stereo-chemical configurationaround the added fusion points will be the same for each of the primaryisomers.

From what has just been said it follows further that given fourhexahalohexacyclododecadienes, formed by the addition of cyclopentadieneto the four hexahalotetracyclododecadienes, the essentialconfigurational differences between them will be those which wereoriginally present in the tetracyclododecadiene generators.

Accordingly, it would appear that in the multiple fused ring compoundswhich I herein disclose the configurational differences of importanceare those which are present around the points of fusion of thehexahalogenated bicycle-heptene ring system and the adjacentbicycloheptene ring system. I shall, therefore, henceforth refer tostereochemical configurations around this fusion line as the basicstereo-chemical configuration of my new compounds: it is thisconfiguration with which I shall be primarily concerned and it is thisconfiguration which will determine for me whether a compound is an alphaseries compound, a beta series compound, etc.

It should be further noted that in addition to the various derivativeswhich can be prepared from my new compounds which have already beenhereinabove discussed it is possible to convert my new beta halogenatedpolycyclic compounds to compositions possessing still another of thefour possible configurations. I shall henceforth call this thirdconfiguration the gamma configuration and shall call the series ofcompounds possessing the gamma configuration the gamma series. This willbe more specifically illustrated in the examples which follow.

It should be clearly understood that, as already noted, the newcompounds of my present invention include both the beta series ofcompounds derived as primary products directly from the Diels-Alderreaction of a cyclopentadiene with a hexahalocycloheptadiene and thecompounds in the beta and gamma series obtained from the productsdenoted above as primary by reaction, with and without rearrangement, atthe reactive double bond of those primary products. The nature of therearrangement which may be involved in producing the gamma series willbe more fully discussed hereinafter: a somewhat more detailed expositionof the relationship existing between the beta and gamma series will alsobe presented. However, let it here be noted that the termallo-configuration is defined as a generic term to denote theconfiguration of those compounds having either the beta or the gammaconfiguration; other configurations are explicitly excluded when theallo terminology is employed. As here employed, the prefix allo,obviously borrowed from the field of steroid chemistry, is to be givenonly the signifiance hereinabove attached to it: it is not intended toconnote the relationships for which it is used in the steroid field.

The diene syntheses can be accomplished most simply by sealing thegenerators into a suitable reaction vessel capable of withstandingpressures up to 300 pounds per square inch and heating the vessel andits contents to a temperature not exceeding 225 C. for a period of oneto twenty hours.

The statement of reaction conditions hereinabove given is actually arecital of the most vigorous conditions which need be employed for thesynthesis of the new compositions of matter which I have discovered. Inthe majority of cases, the reactions proceed rapidly and well attemperatures between 50150 C. and at pressures which are only slightlyabove atmospheric pressure. Actually, it is the vapor-pressure of thelowest boiling generator which determines the operating pressure, andwhen the boiling point of this generator lies above 80 C. the synthesiscan usually be carried out at atmospheric pressure. Of course, if thepolycyclic reactant boils in the temperature range in which the reactionis being conducted provision must be made for its reflux.

These novel halogenated hydrocarbons and hydrocarbon derivatives of myinvention can also be prepared in the presence of suitable solvents. Ingeneral, reactions in solution require a longer period of time thanreactions carried out in the absence of solvent. There is someadvantage, however, which results from the fact that the reaction andthe reaction temperature can be somewhat more easily controlled when asolvent is used.

A wide variety of solvents can be employed 'in carrying out thesepreparations. The rate of reaction will be highest if the solvent chosenhas a boiling point above 80 C. For this purpose, chlorobenzene, xylene,dibutyl ether, etc., can advantageously be chosen. If desired, however,materials such as benzene, toluene, butyl alcohol, dioxane, etc. canalso be used, at the expense, of course, of reaction time.

The examples which follow will serve to illustrate more completely andexplicitly the methods and procedures which may be employed to preparethe new compositions of matter which I have invented. It is, of course,to be understood that these examples are illustrative only and that theyare not to be taken as limiting the scope of my invention.

Examples I, II and III which follow show how the one to one adduct ofcyclopentadiene with1,2,3,4,7,7-hexachlorobicyclo-(2.2.1)-2,5-heptadiene can be prepared.Examples I and II illustrate the preparation of the necessarypolychlorobicyclic diene, as more particularly described and claimed inthe copending application of Bluestone, Serial No. 327,458 filedDecember 22, 1952, and Example III indicates how that diene may bereacted with cyclopentadiene in accordance with the present invention.

EXAMPLE I A 3 liter flask equipped with a sparger and a thermometer Wascharged with 2,550 grams of hexachlorocyclopentadiene having a purity ofapproximately Gaseous vinyl chloride in the reaction vessel wasmaintained at 2 atmospheres (absolute pressure) and the temperature ofthe reacting liquid was maintained at l20i2 C. The reaction wasdiscontinued after 48 hours, and the reaction solution was fractionatedto separate unchanged hexachlorocyclopentadiene and the product. At adistillation pressure of 20 mm. Hg abs. the fraction distilling at122-130 C. was separated; this material was unchangedhexachlorocyclopentadiene. A second fraction, which solidified in thereceiver, boiling between l30150 C. was also collected. This fractionwas melted and transferred to a beaker, cooled and brought on a suctionfilter in order to separate additional hexachlorocyclopentadiene. Theresidue on the filter was dissolved in methanol, and treated withdecolorizing charcoal at the boiling point of the solution; the methanolwas completely evaporated from the solution and the crystals whichresulted were air dried. In this way 694.5 grams of a product meltingbetween l25136 C. was recovered.

Analysis.Calculated for C'zHsCl'z: Carbon, 25.07%, hydrogen, .86%,chlorine, 74.1%. 25.5%, hydrogen, .86%, chlorine, 74.1, 74.4%. I

The compound thus obtained is the adduct of hexachlorocyclopentadienewith vinyl chloride, 1,2,3,4,5,7,7-heptachlorobicyclo-(2.2.1)-2-heptene, presumably correctly representedby the planar structural formula:

01 c1 01 l H EXAMPLE II Heptachlorobicycloheptene (product of Example I)was treated with ethanolic potassium hydroxide solution at the refluxtemperature of ethanol for approximately 4 hours; the solution contained3 moles of potassium hydroxide for each mole of the chloro compoundpresent therein and its concentration with respect to potassiumhydroxide was approximately 3 molar. The reaction mixture became verydark and inorganic salts were thrown out of solution. These salts wereseparated on a filter and most of the ethanol was removed, byevaporation, from the remaining solution. The concentrated solutionwhich resulted was stirred into water and the mixture was acidified withhydrochloric acid. Most of the water was decanted from the resulting twophase mixture and the residue was extracted with diethyl ether. Thisstep in the process resulted in the formation of an emulsion whichseparated only slowly. The separated ether phase was dried overanhydrous sodium sulfate and the ether was evaporated leaving a blackoily material. This black oily material was distilled in vacuo and thecut boiling between 128-145 C. at 18 mm. Hg abs. was collected. Thematerial in fraction represented a yield of approximately 78% based onthe amount of heptachlorobicycloheptene taken for reaction.

Found: Carbon I 1 Analyrz's.Calculated for CrHzCls: Carbon, 28.1%,hydrogen, 0.67%. Found: Carbon, 28.5%, hydrogen, 0.81%.

The compound thus obtained is l,2,3,4,7,7-hexachlrobicyclo (2.2.1) 2,5heptadiene presumably correctly represented by the planar structuralformula:

"k 01 i n 1 01cm I 01 rr EXAMPLE I11 Into a 500 ml. 3-neck round bottomflask equipped with a stirrer, thermometer and reflux condenser wasplaced 299 grams (1 mole) of the hexachlorobicycloheptadiene of ExampleII. While stirring very slowly 46 grams (0.7 mole) of freshly distilledcyclopentadiene was added to the chloro compound. The reaction mixturewas warmed to 65 C. and the lower half of the flask was insulated toretard heat loss. The temperature rose slowly to 98 C.; the temperaturewas then maintained in the vicinity of 100 C. by regulation of thestirring rate. When the reaction ceased to liberate heat and thetemperature dropped to 50 C. another 33 grams (0.5 mole) ofcyclopentadiene was added to the reaction mixture and the solution wasthen heated and maintained between 75-90 C. for 2 hours. At the end ofthat time the mixture was cooled and when the temperature reached 60 C.solid material began to separate. The mixture was rewarmed to 70 C. andpoured into a boiling acetone-methanol mixture. When the solution thusobtained cooled a white crystalline solid separated. This was separatedon a filter and dried; it weighed 210 grams and melted between 240-242"C. Additional crystalline material substantially identical with thatfirst obtained was recovered by concentration of the mother liquor.

Analysis.Calculated for CIZHBClSZ Carbon, 39.49%, hydrogen, 2.21%,chlorine, 58.30%. Found: Carbon, 39.6%, hydrogen, 2.16%, chlorine,58.1%.

The compound thus obtained is beta-hexachlorotetracyclododecadiene (beta1,2,3,4,10,1O hexachloro- 1,4,4a,5,8,8a hexahydro 1,4,5,8dimethanonaphthalene), presumably correctly represented by the planarstructural formula:

01 H /H C] 01001 HCH 01 I H The next three examples, Examples IV, V andVI, demonstrate first, the method which may be used for adding reagentssuch as organic acids, alcohols, etc., to the double bond in theunhalogenated terminal -carbon atom ring ofbeta-hexachlorotetracyclododecadiene and further how the primaryproduct, thus obtained, can be subsequently transformed to other new anduseful eompounds. Example IV illustrates the addition of acetic acid tothe aforementioned compound to produce an acetoxy hexachlorododecene;Example V demonstrates the hydrolysis of this new compound to thecorresponding alcohol and Example VI shows how the alcohol may beoxidized to form the corresponding ketone.

EXAMPLE IV A solution containing 50 grams ofbeta-hexachlorotetracyclododecadiene and ml. of concentrated sulfuricacid dissolved in 180 ml. of glacial acetic acid was refluxed for 20minutes. The reaction mixture was poured into a large volume of waterand the resulting two phase mixture was neutralized with sodiumbicarbonate; the

Cal

organic material was recovered from the resulting mix ture by extractionwith carbon tetrachloride. The carbon tetrachloride solution was placedon a steam bath and evaporated to dryness; the solid organic residuethus recovered was recrystallized from ethanol. There were thus obtained50.4 grams of crystals which were once more crystallized from ethanol.The purified product thus obtained melted between 204208 C.

Analysis.-Calculated for C14H12Cls02: Carbon, 39.56%, hydrogen, 2.79%,chlorine, 50.06%. Found: Carbon, 39.6%, hydrogen, 2.89%, chlorine,50.2%.

The material thus obtained is the acetoxy hexachlorotetracyclododecene(5 -acetoxy- 1 ,2,3 ,4,10,lO-hexachloro- 1,4,4a,5,6,7,8,8a octahydro1,4,5,8 dimethanonaphthalene) presumably correctly represented by theplanar structural formula:

Acetoxy-hexachlorotetracyclododecene (the compound of Example IV) wasconverted to the corresponding hydroxy compound by atrans-esterification procedure. The acetoxy compound was placed insolution in anhydrous methanol containing approximately 7% ofhydrochloric acid by weight and the solution thus obtained was refluxedfor approximately 42 hours; the refluxing was carried out in a flaskfitted with a fairly eflicient fractionating column and a solutionenriched with respect to methyl acetate was removed at the top of thecolumn. At the end of the refluxing period hydrochloric acid and anyremaining methyl acetate was removed by distillation and from theresulting alcoholic solution a white crystalline solid was separated.This material melted with decomposition at 205 C.

Analysis.-Calculated for C12H9Cl6OI-I: Carbon, 37.64%, hydrogen, 2.63%,chlorine, 55.55%. Found: Carbon, 37.7%, hydrogen, 2.75%, chlorine,56.1%.

The material thus obtained is hexachlorohydroxytetracyclododecenel,2,3,4, l0,l0-hexachloro-6-hydroxy- 1,4,4a,5,6,7,8,8a octahydro 1,4,5,8dimethanonaphthalene) presumably correctly represented by the planarstructural formula:

C1 H 01 l l 4011 1 01C 01 HCH 01 H2 Cl H EXAMPLE VIHexachlorohydroxytetracyclododecene (3.8 grams) was dissolved in 100 ml.of glacial acetic acid and to the solution thus obtained there wasgradually added an aqueous solution of potassium permanganate (2.5 gramsin 100 ml. of water). The solution was maintained at C. during theaddition of the oxidizing agent and the temperature of the solution wasthen slowly raised to approximately 100 (steam bath). The temperature ofthe mixture was then permitted to drop to about C. where it wasmaintained for approximately 3 hours. At the end of this time, the solidwhich had precipitated and which contained a mixture of manganesedioxide and the oxidation product, was separated on a filter. Theorganic material was recovered from the mixture with manganese dioxideby extraction with acetone. Evaporation of the acetone from the solutionthus obtained led to the recovery of a crude oxidation product which wasrecrystallized from a mixture of acetone and hexane. There was thusisolated a pure crystalline material melting, with decomposition, at290-291 C.

Analysis.-Calculated for C12HsClsO: Carbon, 37.83 hydrogen, 2.12%,chlorine, 55.85%. Found: Carbon, 38.0%, hydrogen, 2.15%, chlorine,55.8%.

The material thus obtained is ketohexachlorotetracyclododecene(1,2,3,4,10,10 hexachloro 6 keto- 1,4,4a,5,6,7,8,8a octahydro 1,4,5,8dimethanonaphthalene) presumably correctly represented by the followingplanar structural formula:

or H H or o l 01 01 H H 01 I H.

H I/ 01 H Hydrogen can be added to my new diene to form thecorresponding dihydro compound. The preparation ofbeta-hexachlorotetracyclododecene is illustrated in Example VII.

EXAMPLE VII A solution containing 18.3 grams of beta-hexachlorotetracyclododecadiene (0.05 mole) dissolved in 200 ml. of hexane wasplaced in a Parr low pressure hydrogenator. A teaspoonful of Raneynickel catalyst was added to the solution and hydrogenation of themixture was carried out in the usual fashion. Pressure in thehydrogenator dropped approximately 4 pounds in one half hour and thenbecame static. The solution was removed from the hydrogenator and passedthrough a filter to free it of the Raney nickel. Evaporation of thesolvent caused the precipitation of a white crystalline solid. Thissolid melted between 218-219 C. The recovery of product wasquantitative. In contrast to the starting material the product gave acompletely negative test for unsaturation.

Analysis.Calculated for C12H10Cl6: Carbon, 39.28%, hydrogen, 2.75%.Found: Carbon 39.4%, hydrogen, 2.70%.

The product thus obtained is hexachlorotetracyclododecene (1,2,3,4,l0,10hexachloro 1,4,4a,5,6,7,8,8aoctahydro-1,4,5,8-dirnethanonaphthalene)presumably correctly represented by the following planar structuralformula:

01 H H Cl H2 c1 01 H H or E2 l Ex Examples VIII and IX show how halogenderivatives of beta-hexachlorotetracyclododecadiene may be obtained.Example VIII illustrates the preparation of the dichloro derivative ofthe starting material. Example IX details the preparation ofbromohexachlorotetracyclododecene.

EXAMPLE VIII A solution containing 20 grams ofbeta-hexachlorotetracyclododecadiene dissolved in 100 ml of carbontetrachloride was chilled in an ice bath and treated with gaseouschlorine for a period of about 8 minutes. After about minutes thereaction mixture had acquired a distinct yellow color. From theresulting solution a gummy residue was obtained by complete evaporationof the carbon tetrachloride. This residue was taken up in hot methanol;the methanol solution on cooling deposited a white crystalline solid.This solid melted at 212- 213 C.

Analysis.Calculated for C12HsCls: 65.13%. Found: Chlorine, 65.25%.

The solid thus obtained is octochlorotetracyclodode- Chlorine,

cene presumably correctly represented by the following planar structuralformula:

01 H H 01 01 i H 01001 HCH 01 G1 \I H EXAMPLE IXBeta-hexachlorotetracyclododecadiene (0.1 mole) was dissolved in 300 ml.of diethyl ether which had been dried for 18 hours over calciumchloride. The solution was held at 20 C. and anhydrous hydrogen bromideWas passed into it for a 2 hour period. Concentration of the diethylether solution caused the precipitation of a high melting crystallinesolid. Continued evaporation of the diethyl ether mother liquor resultedin the precipitation of a second crop of crystals which, crude, meltedover the range of 145 C. Recrystallization of this material from amixture of acetone and hexane produced a white crystalline solid meltingsharply at 1l0-111 C.

Analysis.-Calculated for ClZHQClGBI'C Carbon, 32.32%, hydrogen, 2.03%,halogen calculated as chlorine, 55,67 Found: Carbon, 32.5%, hydrogen,2.06%, halogen calculated as chlorine, 55.5%.

This material is therefore a bromo-hexachlorotetracyclododecene(6-bromo-1,2,3,4,10,1O hexachloro 1,4, 4a,5,6,7,8,8a-octahydro-1,4,5,8dimethanonaphthalene) presumably correctly represented by the followingstructural formula:

I 0100] G1 I l M H 01 H The fact that reactions occurring at the doublebond in the unhalogenated ring of hexachlorotetracyclododecadiene (suchas are illustrated in Examples IV and IX) can give rise to thederivatives of the gamma series of stereoisomers is particularlynoteworthy. (It should be observed that while Example IV has beenwritten to illustrate the separation of a single acetoxy derivative thereaction procedure there given leads to the formation of two acetoxyderivatives each of which can be isolated in pure form by appropriateseparation methods. Only one method of separation is illustrated. It isbelieved that one of the acetoxy derivatives thus obtained is a betaseries derivative and that the other is a gamma series derivative.) Itis generally believed that when a reaction occurs at the double bond ofa bicycloheptene compound which results in the formation of a carboniumion as an intermediate, the ring system will rearrange; as a result,groups attached to the ethano bridge in the endo position will be foundin an exo position in the new compounds formed in the reaction. Thisstate'ment presupposes that if each of the carbon atoms of the ethanobridge bears a substituent, both of the substituents involved wereoriginally in an endo position. Reasoning from this general assumptionand the fact that a rearrangement occurs it may be inferred that theunhalogenated bicycloheptene ring in my newbeta-hexachlorotetracyclododecadiene possesses an endo configuration andthat the corresponding ring in the gamma compound possesses an emconfiguration. It is my present belief that the halogenated ring in thebeta compound possesses the same configuration as the halogenated ringin the gamma compound and further that the halogenated ring of the alphaseries of compounds is different in its configuration from that of thecorresponding rings in the beta and gamma series of compounds.

I am unable, at the present time, to say with certainty whether theacetoxy derivative of Example IV and the corresponding hydroxy and ketoderivatives of Examples V and VI should be assigned beta or gammaconfigurations. I am similarly uncertain with respect to the bromoderivative of Example IX; in the latter case, however, we are inclinedto believe that it possesses a beta configuration.

The specific illustrative examples hereinbefore given do not, of course,include all of the new compounds in the beta and gamma series which canbe obtained by procedures already known to the art or herein disclosed.Thus, to indicate briefly other reactions which can be utilized for thispurpose the following reaction paths can be cited. Obviously, such arecitation is again only intended to serve as a general guide and is notintended to be complete.

a. Hexabromocyclopentadiene may be caused to react by means of the dienesynthesis reaction with vinyl chloride and the product thus obtained maybe dehydrochlorinated to 1,2,3,4,7,7l1exabromobicyclo-(2.2.1)-heptadiene. This diene may be reacted withcyclopentadiene to give beta-hexabromotetracyclododecadiene.

b. beta-hexabromotetracyclododecadiene may be caused to undergo thereactions hereinbefore illustrated.

c. Beta-hexachlorotetracyclododecadiene can be brominated to form adibromohexachlorotetracyclododecene (beta or gamma).

d. Methyl cyclopentadiene (1-, 2- or S-methylcyclopentadiene) may becaused to react mole for mole with 1,2,3,4,7,7-hexachlorobicyclo (2.2.1)2,5-heptadiene to form a beta-methyl hexachlorotetracyclododecadiene,(i. e. the corresponding 5-, 6-, and 9-methyl-1,2,3,4 .10,10-hexachloro-l,4,4a,5,8,8a-hexahydro 1,4,5,8 dimethanonaphth alenes e.Beta-hexachlorotetracyclododecadiene may be caused to react withcyclopentadiene to form beta-hexachlorohexacyclododecadiene, or withmethyl cyclopentadiene to form the corresponding methyl derivative ofthe hexacyclododecadiene.

Beta hexachlorotetracyclododecadiene dichloride (Example VIII) can bedehydrochlorinated to form beta or gammaheptachlorotetracyclododecadiene.

g. Gamma-hexachlorotetracyclododecadiene can be obtained by thedehydration of gamma-6-hydroxy-hexachlorotetracyclododecene.

Many similar reactions useful for preparing the new compositions of myinvention might be listed. Since, however, such a listing is intendedonly as an aid for the skilled chemist desiring to utilize my inventionit is believed that no useful purpose can be gained by further extendingthe list of reactions already set forth.

While, for the sake of clarity, I have discussed the stereochemistry ofmy new compounds in some detail in an eiTort to elucidate the structuresof these materials, it should, of course, be understood that myinvention is not to be limited by the correctness of the views hereinset forth with respect to reaction mechanisms, stereochemicalconfigurations or structural theory.

These new products of my invention possess, as has already been noted,great practical usefulness as insect toxicants. As has already beennoted, they are completely stable to alkali both in aqueous andnon-aqueous solutions. Moreover, my new compounds exhibit a high degreeof toxicity to a wide variety of insects. This is more specificallyillustrated hereinafter.

Table II shows the toxicity of my new compounds to the common housefly(Musca domestica) in terms of the new halogenated insecticide chlordane,which for this purpose, is rated at 100%. The figures which are shownwere obtained using the Kearns modified small chamber method of test(Soap and Sanitary Chemicals, May, 1948, page 133) and the figures inTable II represent the relationship between the weight of chlordanerequired to produce an LDao and the weight of compound under testrequired to produce this same mortality.

The significance of these tests may be more readily appreciated afterreference to Table I which shows the ratings of the commonly usedorganic halogenated insecticides when compared, in tests similar tothose described above, with heptachlor.

Tests of the insecticidal potency of my new compounds using insectsother than flies attest the generality of their high. insect toxicity.

Thus, for example, my new compound beta-hexachlorotetracyclododecadieneis the most potent material yet available against the roach. This isclearly shown by the data of Table III. As before, relative toxicitiesare indicated in comparison with chlordane which is arbitrarily assigneda value of 100%.

Table III Relative Compound Toxicity,

Percent chlordane (standard) 100 Hepta-chlor 350alpha-hexachlorotetracyclododecadiena 350beta-hexachlorotetracyolododeoadienc 545 The similarly outstandingefiectiveness of my new betahexachlorotetracyclododecadienes astoxicants for the true bugs is indicated by tests using the milkweed bugas the test insect. This insect is employed in evaluation tests as therepresentative of its class, The data obtained are listed in Table IV.As before, chlordane is arbitrarily assigned a value of 100%.

Table IV Relative Compound Toxicity,

Percent chlordane (standard) 100 alpha-Hexachlorotetracyclododccadiene.1, 690 beta-Hexachlcrotetracyclododecadiene 2, 580

However, the greatest utility of my new compounds lies in fieldsunexpectedly difierent from those in which the earlier known members ofthe group are most effective. Thus, While certain of the earlier knownmembers of the group such, for example, asalpha-hexachlorotetracyclododecadiene possess activity against theMexican bean beetle this activity is much lower than the activity of thecorresponding members of the beta series. I have now found that thecorresponding beta compounds are extremely active against this commoninsect pest. The data indicate that, in general, the beta series ofcompounds 1 7 shows higher toxicity to this insect than do thecorresponding compounds of the alpha series. Since this particularinsect tends to exhibit resistance to the halogenated hydrocarbontoxicants normally used to control many other undesirable species suchactivity on the part of my new compounds is particularly surprising.

The resistance of the various aphis species to the action of thehalogenated insect toxicants is many times more marked than that of theMexican bean beetle. In fact, at the present time, only three substancesare effective against the many varieties of this pest, namely,tetraethylpyrophosphate or hexaethyltetraphosphate, parathion andnicotine.

These compounds, because of their high toxicity to mammals, the easewith which they can be absorbed in the body, and the great speed withwhich they act, are dangerous and must be handled with much caution.Moreover, as aphicides, none of them exerts a significant degree ofresidual activity.

I have now discovered that my new compoundbetahexachlorotetracyclododecadiene is extremely efiective against theaphis species. Tests reveal that beta-hexachlorotetracyclododecadiene isthree times as toxic to the aphis as is nicotine sulfate and that it isalmost as toxic to that insect as is parathion.

Because of their physical form, their much lower degree of absorbabilityafter external application to the mammalian body, and their much slowerrate of toxic action toward mammals, my new compounds are far safter toemploy than either parathion or the nicotine salts.

My new compositions of matter are soluble in all of the common organicsolvents and they can be utilized as insect toxicants in all the wayscustomary in the art. Thus they can be dissolved in the insecticide baseoils normally employed (as was done to obtain the data of Table II andTable III) and the resulting solutions sprayed or otherwise employed inthe usual fashion. They can also be combined with finely dividedcarriers to produce wettable and non-wettable insecticidal dusts, theycan be used in the presence of emulsifying agents, with water, and withwater and oils to form insecticidal emulsions. They can also beincorporated in aerosol compositions, and, in general, they can be usedeither as the sole insect toxicant in an insecticidal composition or incombination with other insecticides in order to obtain combinationproperties and other desirable characteristics.

The unusual properties and great stability of my new compounds make themparticularly suitable in a number of less common but highly desirableapplications for insecticidal materials. Thus, they canpbe added tgpfints lac- I A quers, varnishes, and polishing waxes which, after appcation, will give surfaces possessing a high order of insect toxicity.They can be added to paper productsgf all types either by suitableimpregnation of the finished paper materials, or by incorporation duringthe manufacturing process. Similarly they can be added to tackifiers,plasticizers, printing inks, rubber products, etc., in order to providefinished objects possessing inherent toxicity to insect life andresistance to insect attack. They can also be added to varioustypespfwtics and plastic sheetings in order to obtain packaging andwrapping materials themselves resistant to insect attack and able toprotect objects packed in them from such attack, Because of their highresistance to the action of alkali, my new compositions can beincorporated into whitewvashgs and other similar surface coatings. Thoseskilled in the art will, of course, recognize that many other similaruses for these unique compounds are possible, all of which follow fromthe stpecial combination of valuable properties possessed by t em.

It should be noted that my new compositionbeta-hexachlorotetracyclododecadiene appears to possess toxicity to therat to an unusual degree. As a consequence of this fact it can be usedto control this pest when short period toxicity is desired. Thesematerials will be particularly valuable for rodent control in orchardswhere the field mouse and similar rodents present a serious problem;applied to the orchard floor or worked lightly into the topsoil theywill serve not only to destroy the rodent pest but also to eliminateundesirable insect infestation found in and under the ground.

Moreover, many modifications of the basic concepts of my invention herepresented will be evident to those skilled in the arts. Suchmodifications are properly to be included within the scope of mydisclosed invention which is, in no way, to be restricted by the variousillustrative data hereinbefore contained but only by the claims appendedhereto.

I claim as my invention:

l. A compound of the group consisting of (1) l,2,3,4, 10,10 hexachlorol,4,4a,5,8,8a hexahydro 1,4,5,8- dimethanonaphthalene having a meltingpoint when pure of approximately 240 C., its (2) 6-acetoxy-6,7-dihydro,(3) 6-hydroxy-6,7-dihydro, (4) 6-keto-6,7-dihydro, (5) 6,7-dihydro, (6)6,7-dichloro-6,7-dihydro, (7) 6-br0mo- 6,7-dihydro, (8)6-chloro-6,7-dihydro, (9) S-methyl, (10) 6-methyl, and (11) 9-methylderivatives.

2. A compound having the structure:

said compound when substantially pure and in crystalline form having amelting point of from about 240 to about 242 C.

3. A compound having the structure:

Cl H 11 Cl OH CH) Cl H H Cl Br i/ \i/ U1 H said compound whensubstantially pure and in crystalline form melting with decomposition at205 C.

4. A compound having the structure:

H H 01/ l Br I ClC 01 H H C1 B2 said compound when substantially pureand in crystalline form melting at ll011l C.

5. A compound having the structure:

19 8. The method which comprises applying to insects the compound1,2,3,4,10,10-hexachloro-1,4,4a,5,8,Sa-hexahydro-1,4,5,8-dimethanonaphthalene having a melting point whenpure of approximately 240 C.

9. The method which comprises applying to insect habitats the compound1,2,3,4,10,lO-hexachloro-1,4,4a,5, 8,Sa-hexahydro-1,4,5,S-dimethanonaphthalene having a melting point whenpure of approximately 240 C.

References Cited in the file of this patent UNITED STATES PATENTS

1. A COMPOUND OF THE GROUP CONSISTING OF (1) 1,2,3,4, 10,10 -HEXACHLORO - 1,4,4A,5,8,8A- HEXAHYDRO - 1,4,5,8DIMETHANONAPHTHALENEHAVING A MELTING POINT WHEN PURE OF APPROXIMATELY 240* C., ITS (2)L-ACETOXY-6,7-DIHYDRO, (3) 6-HYDROXY-6,7-DIHYDRO, (4)6-KETO-6,7-DIHYDRO, (5) 6,7-DIHYDRO, (6) 6,7-DICHLORO-6,7-DIHYDRO, (7)6-BROMO6,7-DIHYDRO, (8) 6-CHLORO-6,7-DIHYDRO, (9) 5-METHYL, (10)6-METHYL, AND (11) 9-METHYL DERIVATIVES.